[PATCH AUTOSEL 5.18 26/53] libperf evsel: Open shouldn't leak fd on failure

From: Sasha Levin
Date: Mon Jun 27 2022 - 22:20:53 EST


From: Ian Rogers <irogers@xxxxxxxxxx>

[ Upstream commit 94725994cfd768b9ee1bd06f15c252694b1e9b89 ]

If perf_event_open() fails the fd is opened but it is only freed by
closing (not by delete).

Typically when an open fails you don't call close and so this results in
a memory leak. To avoid this, add a close when open fails.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Reviewed-By: Kajol Jain <kjain@xxxxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220609052355.1300162-2-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/lib/perf/evsel.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 210ea7c06ce8..acf8a215dca3 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -149,23 +149,30 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
int fd, group_fd, *evsel_fd;

evsel_fd = FD(evsel, idx, thread);
- if (evsel_fd == NULL)
- return -EINVAL;
+ if (evsel_fd == NULL) {
+ err = -EINVAL;
+ goto out;
+ }

err = get_group_fd(evsel, idx, thread, &group_fd);
if (err < 0)
- return err;
+ goto out;

fd = sys_perf_event_open(&evsel->attr,
threads->map[thread].pid,
cpu, group_fd, 0);

- if (fd < 0)
- return -errno;
+ if (fd < 0) {
+ err = -errno;
+ goto out;
+ }

*evsel_fd = fd;
}
}
+out:
+ if (err)
+ perf_evsel__close(evsel);

return err;
}
--
2.35.1